Intro. to Computer Network › ~victorsun › CN... · Another definition of a computer network (connectivity version): – A connected platform constructed from a set of nodes and

Cheng-Fu Chou, CMLAB, CSIE, NTU

P. 1

Intro. to Computer Network

n  Wed. 2:20pm-5:20pm, in CSIE 101 n  Instructor: Cheng-Fu Chou

–  Email:[email protected] –  Office hours: by appointments

n  TAs: (506) –  林煒晧: [email protected] –  孫哲偉: [email protected]

n  Lecture Format: –  Slides –  Interactive


P. 2

Class Resources

n  Class web page: –  http://www.cmlab.csie.ntu.edu.tw/~victorsun/CN2012/

•  Computer Networks 2012 –  Includes message archives (send by the

instructor or the TA) –  Reading list –  Proj. assignment & HWs –  You should check this site regularly


P. 3

Course Reading

n Textbook: –  “Computer Networking: A Top Down

Approach Featuring the Internet,”5th edition, Jim Kurose and Keith Ross, Addison-Wesley

n  Reference books: –  Computer Networks: A Systems Approach - by

Larry Peterson and Bruce Davie, 4th Edition, Morgan Kaufman, 2007.

–  TCP/IP Illustrated volume I and volume II


P. 4

Important Info.

n Grading: – HW (paper reading and discussion) 20% –  projects (I,II, and III) 35% – midterm 20% –  final 25% –  class participation: 5%


P. 5

Assignments

n HW –  Based on readings and discussions

n Projects: –  C/C++ only –  Paper reading

n Late Policy –  TBD: check the class web site


P. 6

Things to Do Today

n Read class web page –  Check course description


P. 7

Student Commitments

n  Keep up with your reading n Do your own work n Turn in assignments on times n  You are encouraged to study with other

students and discuss (no sharing) programming assignments and HWs


P. 8

Objective n  This course will cover the basic principles

of networking with a focus on protocols, implementations, and issues specific to the Internet. We will selectively implement new protocols and network services; In addition, we will discuss new ideas and issued published in recent network papers in Cloud Computing.


P. 9

Contents

n Computer Networks and Internet n Application Layer n Transport Layer n  The Network Layer


P. 10

Contents

n Wireless and Mobile Networks n Multimedia Networking n Security in Computer Networks n Network Management


P. 11

Question 1

n  Suppose you are at a workstation with IP address 140.112.28.40 and are running IE. You are click on an URL pointing to http://www.youtube.com (IP addr. 64.233.183.91). Assume that the web page is available, loaded and displayed by your browser. Describe, in as much details as you can, the steps that occur between the mouse-click and the displaying of the web page.


P. 12

Ans.

n  6 messages to translate the server name (www.youtube.com) into its IP address

n  3 messages to set up TCP connections n  2 messages for the browser to send HTTP

“get” request n  2 messages for the server to send back

the requested page n  4 messages to tear down the TCP

connections


P. 13

Question 2

n  What are the requirements as you design a computer network


n  Definition of a computer network: –  A shared platform through which a large number of

users and applications communicate with each other.

n  Connectivity: who and how to connect? n  Scalability: how many to connect? n  Resource sharing: how to utilize the connectivity?

–  Packet switching in datacom –  Circuit switching in telecom

P. 14


P. 15

Connectivity: Node, Link, Path (1/2) n Another definition of a computer

network (connectivity version): –  A connected platform constructed from a

set of nodes and links, where any two nodes can reach each other through a path consisting of a sequence of nodes and links.


P. 16

Connectivity: Node, Link, Path (2/2) n  Node: host or gateway

–  Host: end-point where users or applications reside –  Gateway: device to interconnect hosts

n  Link: point-to-point or broadcast –  Point-to-point: two end-points –  Broadcast: many attach-points

n  Path: routed or switched –  Routed: stateless concatenation of links –  Switched: stateful concatenation of links


P. 17

Scalability: Number of Nodes n Another definition of a computer

network (scalability version): –  A scalable platform to group a large number

of nodes so that each node knows how to reach any other node.

n Hierarchy of Nodes n LAN, MAN, WAN

•  LAN: Local Area Network • MAN: Metropolitan Area Network • WAN: Wide Area Network


P. 18

Resource Sharing n  Yet another definition of a computer network

(resource sharing version): –  A shared platform where the capacities of nodes

and links are used to carry communication messages between nodes.

n  How to share? –  Store-and-forward packet switching –  Packetization: message to packets –  Queuing: network of queues

•  At node: queuing/buffering and processing •  At link: queuing/buffering, transmission,

propagation


P. 19

Requirements

n Connectivity n Cost-Effective Resource Sharing n Scalability n What else?


P. 20

Question 3

n  What are the requirements as you design a network for Cloud Computing


P. 21

Requirements

n Connectivity n Scalability n Performance (resource sharing)

–  Reliability & Availability –  Virtualization

n Security and Privacy n What else?


P. 22

The End

n Questions ? –  interested issues, topics

Documents

Intro. to Computer Network › ~victorsun › CN... · Another definition of a computer network (connectivity version): – A connected platform constructed from a set of nodes and